System of electric distribution



2 SheetsSheet 1.

(No Model.)

- E. THOMSON.

SYSTEM OF ELECTRIC DISTRIBUTION.

Patented Apr. 25, 1893.

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E. THOMSON. SYSTEM OF ELECTRIC DISTRIBUTION.

No. 496,020. Patented Apr. 25, 1893.

WEEK FE? MM H -I o 0 WITNESSES- a A A Z INVEHTB SW S T j SS 0 SQ CNSUNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF SIVAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO THETHOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

SYSTEM OF ELECTRIC DISTRIBUTION.

SPECIFICATION forming part of Letters Patent N 0. 496,020, dated April25, 1893.

Application filed December 29, 1890- SerialNo. 376,166. (No model.)

To all whom it may concern.-

Be it known that I, ELIHU THOMSON,2LCltlzen of the United States, and aresident of Swampscott, in the county of Essex and State ofMassachusetts, have invented certain new and useful Improvements inSystems of Electrio Distribution, of which the following is aspecification.

My invention relates to those systems of distribution in which there isa division of the circuits in two parts or portions constitutingtogether what is known as a series multiple are system, and its objectis to provide for an adjustment of the potential in the various parts orportions of the system on changes of load. My invention is designedprincipally, however, as an improvement on a system -heretofore devisedby me (Patent No.

360,125, dated March 29, 1887), and involving the use of energytransformers between the sides or portions of the system designed toabstract energy from a side whose load may fall below normal andtransform it into energy which shall feed a side or portion of thesystem wherever the potential is subject to fall or which becomescomparatively more heavily loaded than the first named portion. WVithtransformers organized to have their sides affected in direct proportionto the change of potential on a side of the system as in that patent,there is a failure of the more heavily loaded side to re-acquire itsfull potential under the action of the energy transferring apparatus,and my present invention is designed to remove the defect, to which endthe invention consists broadly in automatically augmenting the capacityof a side of the apparatus, as generator or motor, as the case may be,so as to bring the transfer up to the full amount and compensatefor thetendency of the heavily loaded side of the system to not quite reach itsnormal potential under the influence of the energy transferring device.In other words I change the relative efficiency of the two sides of themachine, as electro-motive force generators, in accordance with changesin the relation of potential or load on the two portions of the systemin which the potential is to be readjusted.

My invention consists further in the novel methods of compensating orregulating the actions of the energy transferring device applied in asystem of series multiple are dis tribution, and in certain novelcombinations of circuits and apparatus involving the use of a machine ofthe general character described in another application for patent filedby me December 19, 1890, Serial No. 375,197, and wherein I have shown atransformer having an auxiliary magnetic field for a conductorin circuitwith or forming an extension of one of the circuits or windings of thetransformer the two circuits or windings of which, inductively relatedto one another, are in the same magnetic field.

In the accompanyingdrawings:-Figure 1, is a general diagram of apparatusfor practicing my invention. Fig. 2, illustrates a modified apparatusfor practicing the inven tion. Figs. 3, 4 and 7, are longitudinalsections of forms of armature that may be used in the machine. Fig. 5,illustrates a modification of the regulating 0r auxiliaryelectromagnet.Fig. 6, is a further modification in the arrangement of the apparatus.Fig. 8, is a further modification in the manner of exciting theauxiliary or regulating magnet in accordance with changes in therelative load of the two portions of the system between which a transferis to be made.

In Fig. 1, G, is the generator supplying the line with a certainpotential and mains leading therefrom shown at m, m. Branches are takenfrom the mains leading directly to a machine on the line 02, n, whichmachineisa compensator or transformer of electric energy from one sideof the system to the other. The outside lines of the two portions orparts of a system in which changes of load and relation of potentialtake place are indicated at Z, Z, while 0, is the intermediate or middlewire leading from a point of the system between such'two sides orportions. L, are lamps or other devices fed in multiple from one side,and L, devices fed in multiple on the other side. The outside wiresconnect to the mains or wires of constant or approximately constantpotential in the usual way. The machine which effects a transfer ofenergy, (in case the lights L or L, are cut out,) from the lightlyloaded side to the other or ICO heavily loaded side where potential willfall under such circumstances, has upon it two armature windings, andthese armature windings terminate in commutators O, C. The commutatorbrushes, are connected, respectively, as shown to the mains or wires andthe arrangement is such that one of the windings shall at one time actasa motor winding,while the other winding in the field can generatecurrent for the heavily loaded side, or vice versa. Such an arrangementis shown in my prior patent, No. 360,125, and the present invention isan improvement thereon, and is preferably carried outby using mycontinuous current compensator which is compounded for differences ofload.

When the arrangement forming the subject of my previous patent is usedwithout the compensation or regulation such as is herein provided, andthe potential or load drops on one side orportion of the system, thetransfer of energy to the heavily loaded side is insufficient to fullymake good the drop due to the primary change of loading in the otherside, and the heavily loaded side will still have a lower potential thanit should have, while the lightly loaded side will be at a higherpotential than it should be.

In the device or arrangement herein shown in Fig. 1, there is anauxiliary field pole or magnet F, which is made to vary in strength bymeans of the regulating coil D, and which acts on a supplemental orauxiliary armature core A, carrying a winding or part of winding incircuit with or forming an extension of one of the windings acted uponby magnet or core F, which is for the main or principal portion of theapparatus and provides a field that is of substantially constantstrength maintained in any manner for the two armature windings placedon core or section of core A, and connected respectively to the twoportions of the system between which transfer is to be effected.

The windings on the armatures are shown in Fig. 4, where one winding,connected with the commutator C, overlaps the portion of the armaturecore A, while the other winding D, is wrapped over that and theadditional or auxiliary portion A, of the core and is connected to thecommutator C. These windings under normal conditions would be aboutequally effective for electro motive force development when revolving inthe field. The field itself, as shown in Fig. 1, is energized by a shuntcoil S, taken across the mains n, n, to provide constant excitation. Thefield F, is made variable in strength by the action of coil D, eitheralone or in conjunction with another coil so as to secure a differentialaction. In the present instance a coil S in circuit with S, provides anexcitation constant in amount, and the coil D,when traversed loycurrenttends to cut down the magnetism which is normally of a character to actupon the portion of winding moving in it so as to develop anelectromotive force of the same sign in the circuit as that developed byF, in that one of the armature windings with which the former is incircuit. The coil D, is traversed by current which varies with thepotential on the side L, of the system to which commutator O, isconnected. Such a variable current may be caused to flow in any desiredway, automatically or otherwise, and directly or indirectly from suchvariations of potential. It is preferable, however, for simplicity, toconnect the coil D, into a circuit with one of the transformer circuits,as that connected with the side L, of the system. In this way, themagnetism produced by the coil S in the field F, is practicallyconstant, while the magnetism of the other poles or field F, is variablewith the work or load. If preferred the changes of magnetism of thefield F, may be produced by the direct winding D, as in Fig. 5, and theshunt winding S omitted. In this case the coil D, would normally or whenthe load is even or properly proportioned carry no or little current andthe magnetism of F, would normally be of no effect in one way or theother, either to assist or oppose the efficiency of the side of thetransformer connected to C. If the side L, were less heavily loadedcurrent flowing in the coil D, would flow in a direction to developmagnetism in F, of a sign to produce an electro-motive force assistingthe applied electro-motive force in the winding of C, under F, thisbeing the action through the whole range of variations, while in thecase of the differential magnet the action would be first a diminutionof counter tendency passing to zero and then rising in a way to producean electro-motive force assisting. Under very light loads or under evenloads on the two sides of the line 0, the effect is in Fig. 1, that thecoarse winding D, on the accessory field F, is ineffective as it istraversed by little or no current, but on a difference of load existingas though L, were the heavily loaded side and L,were not, then a certaincurrent passing through D, magnetizes the core on which it is wound insuch a way as to increase the potential on the side L, at the expense ofthe potential on the side L. This it would do in the case in question byacting in opposition to the magnetism on the side of the core on whichit is wound or 0pposing the magnetism produced by the coil S on thefield F, thereby rendering the winding connected to the commutator 0,less effective in developing an electro motive force which would opposethe passage of current through the two parts of the winding while notaffecting the field of the commutator O. In other words with a certaindifference of potential on the side L, the coil D, would cut down themagnetism of F, or might carry current sufficient to render it ml or toeven reverse the magnetism in which case the electro-motive forcedeveloped would be now in a direction to assist the appliedelectro-motive force tending to cause flow of current in the winding ofO, which is in the field F. The relative efficiency the side L,

of the two sides of the apparatus or a change in the relation equivalentto a change in the effective length of the two inductively relatedwindings, would therefore be produced and such change would follow thechange in the difierence of potential on the lightly loaded side or thechange in the relative potentials of the two sides of the system. Thiswould make the relation between the windings such that a higherpotential would be developed at 0, than would exist at O, consequentlythe heavily loaded side L, would receive the higher potential andsutficient to restore the normal potential. If the reverse were the caseand L, were the heavily loaded side then the effect would be reversedand the effect on the windings reversed and in any case a compensationeffected. In this case the potential on the side L, being'greater thewinding connected to 0 would carrya greater current While on the side ofless potential L, the electro-motive force developed in the portion ofwinding exposed to the action of F, would rise and would assist orsupplement that developed in that one of the windings in the field of F,which connects to C, and which in such case would raise the potential onthe side L. In this case the armature winding as it now is made to feedthe side L, would pass current through D, in a direction to increase themagnetism of F, and such auxiliary field would serve to augment thetransfer of energy so as to keep up to the normal potential. Either theforms of armatures Figs. 3 or 4, or other forms may be used. In Fig. 3,the portion of the core A, which is a ring core is wound with a set ofcoils connected to the commutator C only, and the two core sections A,A, are wound with another set of coils which are connected with thecommutator O, and the relations of the fields are such that the fieldsurrounds a larger portion of the armature core, and the field F,affects only the portion A, but of course other forms of armature havingthe same properties might be employed and sometimes without an ironcore. In Fig. 5, the direct coil affects the smaller field and does soin the same way as in the former figures only that its efiect is notdifferential, that is the core at times is absolutely dead or free frommagnetism and at other times the core will be afiected by currentpassing through the coil D, in one direction or the other according asenergy is being fed from side L, to L, or from L, to L. In the firstcase when the dilference of potential on the side L, increases withdecrease of load L, and relative increase of load L, the current willpass through the coil D, in one direction to feed the transformerwinding on the side thereof connected to L, and such feeding andconsequent reinforcing action of the additional coil F, will obviouslycontinue so long as a variation from normal difierence of potentialexists. In this case the magnetism of F, will produce an electro-motiveforce tendency aiding the winding of the transformer which is for thetime being the motor winding and is required to transfer energy to theheavily loaded side, just as in the ease of Fig. 1, where the current inD, is sufficient in amount to reverse F, and give it a polarity due tothe winding of D. In the other case when the difference of potentialfalls on the heavily loaded side L, and current is therefore fed fromthe side of the transformer connected to L, the auxiliary coil D, willbe traversed by current in the opposite direction and the electro-motiveforce will be raised by the action of the supplemental field magnet F,which will now be of polarity to assist that developed in thetransformer winding feeding under the action of F.

In Fig. 2, the arrangement is a little modified since the energytransferring portion of the machine is separated into two machines andthe two armatures connected together, that is I may have in the machine,if I choose, two armatures A and A, of the same or of different size oneaffected by the shunt field and geared or belted one to the other, thearmature A, being affected by the shunt field and also by the directfield. By proportioning the parts the same effects may be obtained as inthe machine Fig. 1, but it is not a desirable structure as it involvestwo machines, and involves also an adjustment of the commutator whichobjections are largely avoided by the construction Fig. 1.

Another modification similar in its effects is seen in Fig. 6. Here theeffect is the same, but there are three commutators. The armature A, hastwo windings and the second auxiliary armature A, has its singlewindingconnected to the commutator C The larger armature A, with its twowindings is affected only by the shunt coil S, or other eoil acting uponits field and the smaller armature A, is affected by the direct andshunt windings D, S, as before, or the direct coil only (D,) maysometimes be employed. The two windings one connected to the commutatorO, and the other to G on the small armature, virtually act as onewinding by being connected in series as shown and therefore take theplace of the arrangement Fig. 7

The arrangement Fig. 7, is a combination of what is shown in Figs. 3 and4:, that is the armature section or armature core section A, is shown asa ring and has, a winding which connects to the commutator C, while thearmature core section A, is a Siemens core which has a winding passingover the main armature section and over this core and terminating in thecommutator O. Manifestly the effects are the same as in the formerfigures, the only difference being that the field has to be modified inits proportions and an rangements to suit.

Fig. 8, illustrates a modification in the mannor of providing for avariable auxiliary excitation acting upon a side or circuit of thetransformer to change in the relative electromotive force efficiency inaccordance with changes in the load. In this case the said variablefield is produced by one or the other of two coils D, D, which opposeand neutralize one another when the load is even and which are connectedwith the main wires leading to the two sides of the system. When theside L, has the greater load, the coil D, in the main circuit of suchside has the greater current and develops magnetism which assists theside of the tranformer which is abstracting energy from L, for transferto L, just the same as the coil D, Fig. 5. When the other side L, hasthe greater load the coil D, which is wound in the opposite directionhas the greatest current and acts just as the coil D, Fig. 5, toreinforce side 0, of the transformer operating as a generator.

It will be obvious that my invention is not limited to the number ofdivisions of the system which are to have their relations of potentialkept uniform. It is likewise obvious that the invention is not confinedto applying the auxiliary or compensating action to a single side of theenergy transferring devices only, and although in my claims I mentionone side as having the device applied, I do not of course exclude itssimultaneous application to the other side. If applied, however, to theother side or sides, the regulating action would of course be in theopposite way so as to decrease the effectiveness on one side whensimultaneously increasing it in the other or vice versa.

What I claim as my invention is- 1. The herein described method ofsupplementing the transfer of energy from one to another portion of asystem of electrical distribution so as to avoidadrop of potential onthe heavily loaded portion, consisting in varying an auxiliary magneticfield in accordance with changes in the relation of the load on the saidportions'of the system between which the transfer is to take place andsubjecting a moving conductor in circuit with an armature conductor ofthe transfer apparatus to the action of such field.

2. The herein described method of regulating the action of anenergytransferring apparatus placed between different portions of a circuitsubject to changes in their relative loads, consisting in subjecting oneor both sides of the machines to the action of an auxiliary regulatingcoil or coils, and varying the current in such coil or coils inaccordance with the changes in the relation of the loads in the twoportions of the circuit between which a transfer is to take place.

3. The herein described method of regulating the transfer of energy fromeither side to the other of a system of distribution, consisting intransferring the energy from that side on which the potential risesabove the normal to that on which it falls below, and at the same timevarying a magnetic field or fields acting upon the circuit of one orboth sides of the transfer apparatus so as to supplement or augment thetransfer and restore the poten tials to normal.

4- In a transfer apparatus connected to circuits as and for the purposedescribed, the method of regulating the capacity of the ma- China intransferring energy from a more lightly loaded to a more heavily loadedpart of the system, consisting in subjecting a side or portion of the,apparatus to the action of an auxiliary or compounding or regulatingcoil carrying current varying with the load, and adapted to change therelative efficiency of two sides of the transfer apparatus.

5. In a system of electric distribution, the herein described method ofregulating the distribution of energy in difierent parts or portionsthereof, consisting in transforming or converting the energy of the sideon which the potential rises into energy on a side or portion in whichthe potential falls, and varying an auxiliary magnetic field for aconductor in circuit with a coil or conductor of the transformingapparatus in accordance with varia tions in the relative proportions ofload on the two portions of the system from normal.

6. The combination with a series multiple are system, of acontinuous-current energytrans'former connected to main and middle orintermediate wires, and provided with a compounding or regulating fieldmagnet coil D, as and for the purpose described.

7. In a system of electric distribution, the combination with two partsor portions of circuit fed from the same mains but subject to variationsof the relative potential from normal, of a converter comprising twoarmature circuits or conductors connected to said parts and revolving ina common magnetic field, and an auxiliary magnetic field variable with achange in the relative load on the two parts and constituting a fieldfor the conductor which forms an extension of the circuit of saidarmature conductors.

8. In a multiple series system of distribution, the combination withsides or portions of the system in which the relation of potential issubject to variation, of a converter connected to the outer wires and anintermediate wire of said portions, transformer circuits or conductorsconnected respectively to said portions and in a common magnetic field,an auxiliary variable field variable with the load of a side or portionof the system, and a conductor therein forming an extension of thecircuit of one of said tr? nsformer circuits.

9. The combination with a multiple series system of distribution, of anenergy transferring apparatus connected to the outer and intermediatewires of portions of the system subject to change of load and comprisingconnected armature circuits or conductors mounted on the same orconnected shafts and revolving in a suitable field or fields, and anauxiliary field magnet coil for augmenting or reinforcing the action ofa side of the apparatus, as motor or as generator, according to thechanges of potential on the side or portion of the system to which it isconnected.

10. In a system of electric distribution,the combination with twoportions of the circuit subject to changes in their relative potential,of sets of armature Wires or conductors mounted on the same shaft andrevolving in the same field, a connection from one terminal of botharmatures to an intermediate wire of the system, connections from theremaining terminals to outer wires of the system respectively, anauxiliary variable magnetic field, and an armature conductor revolvingtherein and included in the circuit from one of said armature terminals,as and for the purpose described.

11. The combination with outer and intermediate Wires for differentportions of a system of distribution, of an armature carrying dififerentwindings connected to said wires as described, an auxiliary armature,and a differential field-magnet therefor wound with two coils onecarrying constant current and the other current varying with thepotential on a side of the system, said auxiliary armature havingconductors in the circuit of awinding on the former armature, as and forthe purpose described.

12. The combination with a system of distribution, of an armatureA,having two Windings, an armature A, having awindingforming anextension of a Winding upon the first, a constant magnetic field for thefirst armature, an auxiliary field magnet for the armature A, a coil orcoils for said field magnet carrying current varying with the load on aside or portion of the system, connections from both armature windingsto an intermediate portion of the system, and connections from theopposite terminals of the armature windings to outer Wires of the twoportions of system subject to variations in their relative potential.

Signed at Lynn, in the county of Essex and State of Massachusetts, this22d day of December, A. D. 1890.

ELIHU THOMSON.

\Vitnesses:

JOHN W. GIBBONEY, BENJAMIN B. HULL.

